BY T. W. EDGEWORTH DAVID. 487 



With this it may be of interest to compare a descending section 

 of the Torbanehill seam in Scotland by Thomas Stuart Traill, M.D., 

 F.R.S.E.^ 



1. "A thick roof of sandstone. 



2. Faeks, a crumbling shale = 4 inches in thickness. 



3. Cement, a mixture of shale and poor ironstone = 3 inches. 



4. Bituinenite, which in this pit at the face => 1 foot 4 inches in 



thickness (elsewhere 1 foot 11 inches, T.W.E.D.). 



5. Fine ironstone from 2 inches to \ inch. 



6. Bituminous shale often containing tabular masses of good iron- 



stone — 2 inches. 



7. An inferior coal = 7 inches. These four last-mentioned beds are 



all raised with the Bitumenite, and together measure 2 feet 



3 inches in thickness. 



8. Coal much mixed with shale, here called ybit/ coal, about 2 feet 



4 inches. 



9. Fireclay." 



The " Bitumenite " above is a synonym proposed by Dr. Traill 

 for Torbanite. 



On p. 10 (loG. cit.) he states that large Stigmarice occur in the Tor- 

 banite, one as thick as a human body, and also that no real organic 

 structure was visible in the Torbanite, but numerous globules of a 

 pale yellowish matter. In the same publication, p. 176, Dr. 

 John Hughes Bennett, M.D., F.R.S.E., describes minute trans- 

 parent bodies in the Torbanehill Mineral having a radiate crystal- 

 line appearance, and being from sJo^-h to 4000th of an inch in diameter. 

 He states (loc. cit. p. 181) that these yellow masses in the Torbane- 

 hill Mineral are a " bitumenoid or resinoid substance, imbedded in 

 earthy matter ;" and also that " We could nowhere discover in 

 them any trace of cell wall or contents. , . . Numbers of 

 them present no envelope or definite boundary." 



* Trans. Roy. Soc. Edinburgh, xxi. Part 1, p. 8. 



